1. Technical Field
The present invention relates to a translucent solar cell and, more particularly, to a translucent solar cell enhanced in light transmissivity and configured to prevent short-circuiting during the manufacturing process.
2. Description of Related Art
A thin-film solar cell is manufactured by depositing various films on a substrate and then laser-scribing the films so as to form discrete and series-connected unit cells. More specifically, a front electrode layer, a photoconductive layer, and a back electrode layer are deposited sequentially on the substrate. In the prior art of thin-film solar cells, U.S. Pat. No. 4,795,500 discloses a solar cell shown in FIG. 1A, wherein the solar cell includes a substrate 1, a photoelectric conversion element 2 (composed of a front electrode layer 3, a photoactive layer 4, and a back electrode layer 5), and a resist layer 8. To make this solar cell, the resist layer 8 is used as a photo mask, and a plurality of light-transmissive regions 6 are formed as desired through an etching process.
U.S. Pat. No. 6,858,461 teaches another solar cell, as shown in FIG. 1B. The solar cell, indicated by the reference numeral 110 in FIG. 1B, includes a substrate 114, a front electrode layer 118, a photoactive layer 120, and a back electrode layer 122. The solar cell 110 is laser-scribed to form scribe lines 124 perpendicular to the grooves 128 dividing the solar cell 110 into discrete and series-connected unit cells 112. Then, the metallic back electrode layer 122 is partially removed to form light-transmissive regions which allow the passage of light emitted from a light source 116, thus creating translucency. In addition, US Patent Publication No. 2006/0112987 discloses yet another solar cell, as shown in FIG. 1C, wherein a multitude of holes 8 are formed by partially removing a back electrode layer or a photoconductive layer with laser. These holes 8 provide the solar cell module 19 with a plurality of light-transmissive regions 18 that render the entire solar cell module 19 translucent.
In order to allow the passage of light and achieve translucency, the above-cited thin-film solar cells are formed with a plurality of light-transmissive regions. However, while the light-transmissive regions are formed, i.e., while the films are partially removed by laser or by an etching process so as to create holes or scribe lines on the films, a thermal effect tends to take place upon cutting the films, such that the portions of the films that are supposed to be cut off to form the holes or the scribe lines are not completely removed. As a result, the conductive layers are bridged and cause short circuits.